Valiant scientist Dr. Cory (Lew Ayres) knows he must resort to unorthodox methods in order to save ailing tycoon Tom Donovan, so the surgeon removes the wealthy man’s brain and manages to keep it functioning with electrical stimulation. Unfortunately, it isn’t long before Donovan’s brain somehow possesses the kindhearted Dr. Cory, who then begins to behave like the heartless Donovan. Cory’s wife, Janice (Nancy Davis), and friend Dr. Schratt (Gene Evans) try to intervene, with horrific results.